Zusammenfassung der Ressource
P6: Radioactive Materials
- Types of
radiation
- Gamma
- Least Ionising, most
penetrating-few cm of
lead, no charge
- Beta
- Mid Ionising, Mid
penetrating-thin metal
, negative charge
- Alpha
- Most Ionising, Least
penetrating-paper/skin,
positive charge
- What is nuclear fusion?
- When 2 hydrogen nuclei
in the atoms are brought
close together and fuse-
releasing energy
- What are Isotopes?
- Atoms of an element that have
a different mass number due to
a different number of neutrons
- E=mc²
- E=ENERGY PRODUCED
m=change in mass
c=speed of light
calculates the amount
of energy released
during nuclear fission
and fusion
- Half life- time
taken for number
of atoms to halve
from decay
- Radioactive Decay- the spontaneous
change in an unstable element, giving out
alpha, beta or gamma radiation. Alpha
and beta emission result in a new
element
- Radiation Sources
- Natural
- 84%
- 50% from
radon gas in
the ground
- 12% from
cosmic
rays
- 9.5% from
food and
drink
- 13% from gamma
rays from the
ground and
buildings
- Artificial
- 15% medical
- 16%
- What is nuclear fission?
- The process when a nucleus of
uranium-235 breaks apart,
releasing energy, when it
absorbs a neutron
- Nuclear fuel-in a nuclear
reactor, each uranium
atom in a fuel rod
undergoes fission and
releases energy when hit
by a neutron
- Radiotherapy-using high
doses of ionising to kill
cancerous cells/x-rays in the
body
- Sterilisation-gamma
radiation kills
microorganisms through
packaging in medical
equipment
- Why is ionising radiation dangerous?
- Ionising radiation has the energy to break
molecules in the cells in the body into
ions. These ions can then take part in
chemical reactions that might damage the
body. If the ionising radiation affects DNA
molecules, this may cause the cell to be
killed or behave abnormally, which can
cause cancer.